Question

a) What is a solar cell made up of?
b) State the energy transformation that takes place in a solar cell.
c) Give any two uses of the solar cells.

Answer 1

(a)

1. A solar cell is made up of Silicon.
2. A solar cell or photovoltaic cell is an electrical device that converts the energy of the light directly into electricity by the photovoltaic effect.
3. A solar cell is constructed by selecting suitable material so that it’s easy to generate current.
4. It is based on the principle that when solar radiation falls on the surface of the metal in a solar cell, the electrons on the surface of the metal get excited and hence current is generated.
5. 

(b)

1. The photocurrent is the current produced when light falls on a photodiode or a metal with a suitable work function.
2. Work function is defined as the minimum energy required to eject an electron from the surface of the material.
3. It also corresponds to the minimum frequency, the photon of which when falls on the surface of a metal, the photoelectron gets ejected.
4. This phenomenon of the ejection of an electron is known as the photoelectric effect.
5. A solar cell is constructed by selecting suitable material so that it’s easy to generate current.
6. Generally, the material having less work function is selected.
7. It is based on the principle that when solar radiation falls on the surface of the metal in a solar cell, the electrons on the surface of the metal get excited and hence current is generated.
8. This current is collected by applying certain potential differences across the solar cell.
9. 

(c)

1. Solar cells are used to convert light sources from the sun into electrical energy.
2. Solar cells are used in power farms to provide electricity to large areas.
3. Solar cells used in vehicles like cars, buses etc. help to save non-renewable fuel.